Fluid logic circuit and shift register employing same



March 15, 1966 D. R. JONES 3,240,220

FLUID LOGIC CIRCUIT AND SHIFT REGISTER EMPLOYING SAME Filed Feb. 26,1965 2 Sheets-Sheet 1 INVENTOR.

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FLUID LOGIC CIRCUIT AND SHIFT REGISTER EMPLOYING SAME Filed Feb. 26,1963 2 Sheets-Sheet 2 INVENTOR D. Rom/v0 JONES Mum? United States Patent3,240,220 FLUID LOGIC CIRCUIT AND SHEET REGISTER EMPLOYING SAME DonnieRoland Jones, Silver Spring, Md, assignor to Eowles EngineeringCorporation, Silver Spring, Md.,

a corporation of Maryland Filed Feb. 26, 1963, Ser. No. 261,180 8Claims. (Cl. 137--81.5)

The present invention relates to pure fluid logic elements and, moreparticularly, to a twin and-gate for use in fluid logic systems.

The apparatus of the present invention is related to pure fluid systemsof the general type described in US. Patent No. 3,024,805 issued toBilly M. Horton; Patent Nos. 3,001,698 and 3,016,066 issued to RaymondW. Warren and Patent Nos. 3,001,539 and 3,004,547 issued to HymanHurvitz.

The twin and unit of the present invention is of general applicabilityin pure fluid digital systems but is described in terms of itsapplication to a pure fluid counter or shift register.

In a pure fluid counter or shift register, for purposes of discussion,as in other types of digital shift registers, it is necessary inresponse to a timing signal to shift information into or out of theregister without losing the information as it is stepped from stage tostage therethrough. Numerous schemes have been suggested foraccomplishing this result in pure fluid systems but each of the priorart devices have suffered from one or more difliculties; such as lack ofsensitivity to input signals, criticality of parameters and sensitivityto environmental conditions.

It is an object of the present invention to provide a twin and gatewhich provides a high degree of reliability and which is relativelyinsensitive to environmental conditions.

It is another object of the present invention to provide a twin and unithaving a high degree of sensitivity to input signals.

Still another object of the present invention is to provide a twin andunit which may be employed in pure fluid shift registers.

The above and still further objects, features and ad vantages of thepresent invention will become apparent upon consideration of thefollowing detailed description of one specific embodiment thereof,especially when taken in conjunction with the accompanying drawings,wherein:

FIGURE 1 of the accompanying drawing illustrates the pure fluid twin andunit of the present invention; and

FIGURE 2 illustrates two fluid flip-flops interconnected by a twinand-unit to provide a shift register.

Referring specifically to FIGURE 1 of the drawings, there is provided apure fluid device formed as channels in a plate 1 wihch may be ofplastic, glass, or other suitable material. In use, the top surface ofthe plate 1, as viewed in FIGURE 1, is adapted to be covered by afurther plate which forms a fluid-tight seal between the further plateand the surfaces of the plate 1 which are not recessed. In this way,fluid supplied to the apparatus is confined to the fluid paths formed aschannels in the plate.

The apparatus of FIGURE 1 comprises a first nozzle 2 employed as atrigger or timing pulse input to the apparatus. The fluid is supplied tothe nozzle 2 through an input aperture 3 adapted to have fluid suppliedthereto at relatively precisely timed intervals. Located to the left ofthe nozzle 2 as viewed in FIGURE 1 of the accompanying drawing. is asecond nozzle 4 lying at a predetermined angle relative to thecenterline of the "ice nozzle 2. The nozzle 4 is supplied with fluidthrough an aperture 6 and, when fluid is supplied through the aperture6, the nozzle 4 issues fluid which intercepts fluid issued by the nozzle2 if such fluid is being issued at that time. Positioned to the right ofthe nozzle 2, as viewed in FIGURE 1, is a third nozzle 7 adapted to havefluid supplied thereto through a passage 8 in the plate 1. Thecenterline of the nozzle 7 lies at approximately the same angle relativeto the centerline of the nozzle 2 as the centerline of the nozzle 4.

In general, the fluid issued by the nozzle 2 follows a path indicated byan arrow 9; fluid issued by the nozzle 4 follows a path indicated by anarrow 11; and fluid issued by the nozzle 7 follows a path indicated bythe arrow 12. The apparatus is provided, in effect, with five outletpassages. A center passage 13 is positioned downstream and along thecenterline of the nozzle 2 so that fluid issued by this latter nozzle,if not intercepted by any other fluid stream, flows directly to theoutlet passage 13. The passage 13 is employed as a fluid dump; that is,the fluid entering this passage may be vented directly to the atmospherethrough a passage 14 formed in the plate or may be returned to the pumpsupplying fluid under pressure if the system is to be employed as aclosed system. A further outlet passage 16 is positioned at the rightside of the apparatus as viewed in FIGURE 1 and is employed to collectundeflected fluid issued by the nozzle 4. Fluid flowing to the outletpassage 16 may flow through a passage 17 in the plate 1 to the ambientatmosphere or to the return side of the pump. The passage 16 also servesto defeat boundary layer effects in that it removes sidewalls from theapparatus which might otherwise be present and which, if present, mightinfluence the paths of flow of the various fluid streams in theapparatus. A third outlet channel or passage 18 is formed at the leftside of the apparatus as viewed in FIG URE 1 and is generally a mirrorimage about the center line of the nozzle 2 of the outlet passage orchannel 16. The passage 18 is adapted to receive an undeflected streamissued by the nozzle 7 and also serves to prevent boundary layer effectsat the left side of the device.

The apparatus is provided with two further outlet passages having rathernarrow inlet openings. These passages constitute signal output channelsand are designated by reference numerals 19 and 21, respectively. Theinput orifices to the channels 19 and 21 are quite narrow so as tominimize the possibility of fluid entering these passages in the absenceof fluid streams being directed precisely at their openings. Thisfeature is not absolutely essential to the operation of the system butdoes impart a high degree of reliability to its operation.

In the operation of the apparatus, the input orifices 6 and 8 wouldnormally be connected to sense the condition of some prior stage orstages of a pure fluid system. This is not an essential mode ofoperation of the apparatus since signals applied to these nozzles may bederived from transducers but, for purposes of explanation, it will beassumed that they receive fluid from pure fluid devices.

The system is such that, if fluid is applied initially to the nozzle 4at a time T, when fluid is supplied to the nozzle 2, the fluids issuedby nozzles 2 and 4 interact and the stream formed by the confluence andinteraction of these two streams follows a path indicated by an arrow22. This path is directed at the entrance to the right output passage 21and thus, under these circumstances, fluid is supplied during theinterval T to this passage. During all other intervals; that is, aninterval when a fluid is not supplied to the nozzle 2, fluid supplied tothe nozzle 4 follows the path indicated by the arrow 11, passes throughthe channel 16 and is dumped. If a signal is not applied to the passage4 at the time T then the stream issued by the nozzle 2 enters passage 13and is dumped. Thus, the elements comprising nozzles 2 and 4 andpassages 13, 16 and 21 constitute a two-input and gate.

1 If, during an interval T fluid is supplied to the nozzle 7, thestreams issued by nozzles 2 and 7 interact and produce a further streamhaving a flow path indicated by an arrow 23. This flow path is directedat the entrance of the output passage 19 and thus, when fluid issupplied to nozzles 2 and 7 concurrently, fluid is supplied to theoutput passage 19. If fluid is supplied only to the nozzle 7, it followsa path indicated by the arrow 12 and flows through the passage 18.Again, if fluid is issued only by the nozzle 2, it enters the passage 13and is dumped. Thus, the device including the nozzles 2 and 7 andpassages 13, 18 and 19 constitutes a second two-input and unit.

If the unit of FIGURE 1 is to be employed in a shift register, theorifices 6 and 8 are connected to two output channels 24 and 26,respectively of a single flip-flop 27. The output channels 19 and 21 areconnected to two control nozzles 28 and 29, respectively of a subsequentflip-flop 31. If fluid is supplied to the nozzle 4, this indicates thatthe flip-flop 27 of the prior stage of the register has fluid suppliedto its left output channel 24. Upon the application of a trigger orstepping impulse to the nozzle 2, fluid flows through the passage 21 toa right control nozzle 29 of the next stage of the register and causesthe flip-flop to switch its flow, if it is not already so directed, toits left output channel 32 of that stage. Thus, the conditionestablished in the stage prior to the illustrated apparatus is passedalong to the stage following the illustrated apparatus.

It will be noted that, if fluid is issued by both nozzles 4 and 7concurrently or nozzles 2, 4 and 7 concurrently, ultimate flow is alongthe path indicated by the channel 9. Thus, in certain applications, oneor the other of the nozzles 4 and 7 may be employed as an inhibitinginput to the system, further extending the utility of the device.

While I have described and illustrated one specific embodiment of myinvention, it will be clear that variations of the details ofconstruction which are specifically illustrated and described may beresorted to without departing from the true spirit and scope of theinvention as defined in the appended claims.

What I claim is:

1. A pure fluid logic element having and gate characteristics comprisinga first nozzle for issuing a first stream of fluid, a first outletpassage positioned downstream of said first nozzle and generally alignedwith the centerline of said first nozzle, a second nozzle disposed onone side of said first nozzle and posiitoned to issue a second stream offluid into intercepting relationship with said first stream of fluid, asecond outlet passage positioned downstream of said second nozzle andgenerally aligned with the centerline of said second nozzle forreceiving said second stream when undeflected, a first output passagepositioned to receive a first composite stream of fluid resulting fromconfluence and interaction of said first and said second stream offluid, a third nozzle disposed on the other side of said first nozzleand positioned to issue a third stream of fluid into interceptingrelationship with said first stream of fluid, a third outlet passagepositioned downstream of said third nozzle and disposed generally alongthe centerline of said third nozzle for receiving said third stream offluid, and a second output passage positioned to receive a secondcomposite stream of fluid resulting from confluence and interaction ofsaid first and said third streams of fluid.

2. A pure fluid twin and unit comprising means for issuing a firststream of fluid, means for issuing a second stream of fluid intointercepting relationship with said first stream of fluid, means forissuing a third stream of fluid into intercepting relationship with thefirst and second streams of fluid, first output means positioned tointercept a fourth stream of fluid formed by the confluence of saidfirst and second streams of fluid, second output means positioned tointercept a fifth stream of fluid formed by confluence of said first andthird streams of fluid, and outlet means aligned with the other of saidstreams of fluid and being larger than said means for issuing the otherof said streams of fluid. 1

3. The combination according to claim 2 wherein said outlet meanscomprises a plurality of channels including a first channel positionedto receive said second stream of fluid when undeflected, a secondchannel positionedto receive said third stream of fluid when undeflectedand a third channel positioned to receive said first stream of fluidwhen undeflected and a sixth stream of fluid formed by the confluence ofsaid second and thirdstreams of fluid.

4. The combination according to claim 1 further comprising a first and asecond pure fluid flip-flop, each having a power nozzle, left and rightcontrol nozzles and left and right output channels, means connectingsaid left output channel of said first flip-flop to said second nozzleof said logic element, means connecting said right output channel ofsaid first flip-flop to said third nozzle of said logic element, meansconnecting said first output passage of said logic element to said rightcontrol nozzle of said second fluid flip-flop and means connecting saidsecond output passage of said logic element to said left control nozzleof said second flip-flop.

5. A shift register comprising a plurality of fluid flipflops, each ofsaid fluid flip-flops including at least a power nozzle for issuing apower stream of fluid, a pair of receiving apertures situated downstreamof said power nozzle and a pair of control nozzles for issuing controlstreams of fluid into intercepting relation with said power stream fromopposite sides thereof to deflect said power stream selectively to oneand the other of said apertures, a plurality of fluid amplifiers withand gate characteristics having at least a power nozzle for issuing apower stream of fluid, a pair of receiving apertures positioneddownstream of said power nozzle, and a pair of control nozzles forissuing control streams of fluid into intercepting relationship withsaid power stream of said amplifier from opposite sides thereof, saidnozzles and said apertures of said fluid amplifier being positioned suchthat fluid is dirrected to one of said apertures only in the presence ofsaid power stream and one of said control streams of said fluidamplifier outlet means positioned for receiving said amplifier controlstreams in the absence of said power stream, means connecting one fluidamplifier between each pair of fluid flip-flops with said controlnozzles of said amplifier each being connected to a different one ofsaid apertures of one of said flip-flops and each of said apertures ofsaid amplifier being connected to a different control nozzle of anotherof said flip-flops and means for selectively applying fluid to saidpower nozzle of said amplifier to step information through saidregister.

6. A shift register comprising a plurality of fluid flipflops, each ofsaid fluid flip-flops including at least a power nozzle for issuing apower stream of fluid, a pair of receiving apertures situated downstreamof said power nozzle and a pair of control nozzles for issuing controlstreams of fluid into intercepting relation with said power stream fromopposite sides thereof to deflect said power stream selectively to oneand the other of said apertures, a fluid and-gate connected between saidapertures of one of said flip-flops and said control nozzles of anotherof said flip-flops said fluid and gate having outlet means for receivingthe undeflected stream from said apertures, and means for pulsing saidfluid and-gate to apply the fluid flow pattern established at theapertures of said one flipflop to the control nozzles of the other ofsaid flip-flops to step information through said register.

7. A shift register comprising a plurality of fluid flipflops, each ofsaid fluid flip-flops including at least a power nozzle for issuing apower stream of fluid, a pair of receiving apertures situated downstreamof said power nozzle and a pair of control nozzles for issuing controlstreams of fluid into intercepting relation with said power stream fromopposite sides thereof to deflect said power stream selectively to oneand the other of said apertures, fluid logic means having and gatecharacteristics connected between said apertures of one of saidflip-flops and said control nozzles of another of said flip-flops saidfluid logic element having outlet means generally aligned with saidapertures for receiving the undeflected stream from said apertures, andmeans for pulsing said fluid logic means to apply the fluid flow patternestablished at the apertures of said one flip-flop to the controlnozzles of the other of said flip-flops to step information through saidsystem.

8. The combination according to claim 1 wherein said second and thirdoutlet passage are positioned so as to maintain ambient pressure onopposite sides respectively of a stream of fluid issued by said firstnozzle.

References (lited by the Examiner UNITED STATES PATENTS M. CARY NELSON,Primary Examiner.

LAVERNE D. GEIGER, Examiner.

1. A PURE FLUID LOGIC ELEMENT HAVING AND GATE CHARACTERISTICS COMPRISINGA FIRST NOZZLE FOR ISSUING A FIRST STREAM OF FLUID, A FIRST OUTLETPASSAGE POSITIONED DOWNSTREAM OF SAID FIRST NOZZLE AND GENERALLY ALIGNEDWITH THE CENTERLINE OF SAID FIRST NOZZLE, A SECOND NOZZLE DISPOSED ONONE SIDE OF SAID FIRST NOZZLE AND POSITIONED TO ISSUE A SECOND STREAM OFFLUID INTO INTERCEPTING RELATIONSHIP WITH SAID FIRST STREAM OF FLUID, ASECOND OUTLET PASSAGE POSITIONED DOWNSTREAM OF SAID SECOND NOZZLE ANDGENERALLY ALIGNED WITH THE CENTERLINE OF SAID SECOND NOZZLE FORRECEIVING SAID SECOND STREAM WHEN UNDEFLECTED, A FIRST OUTPUT PASSAGEPOSITIONED TO RECEIVE A FIRST COMPOSITE STREAM OF FLUID RESULTING FROMCONFLUENCE AND INTERACTION OF SAID FIRST AND SAID SECOND STREAM OFFLUID, A THIRD NOZZLE DISPOSED ON THE OTHER SIDE OF SAID FIRST NOZZLEAND POSITIONED TO ISSUE A THIRD STREAM OF FLUID INTO INTERCEPTINGRELATIONSHIP WITH SAID FIRST STREAM OF FLUID, A THIRD OUTLET PASSAGEPOSITIONED DOWNSTREAM OF SAID THIRD NOZZLE AND DISPOSED GENERALLY ALONGTHE CENTERLINE OF SAID THIRD NOZZLE FOR RECEIVING SAID THIRD STREAM OFFLUID, AND A SECOND OUTPUT PASSAGE POSITIONED TO RECEIVE A SECONDCOMPOSITE STREAM OF FLUID RESULTING FROM CONFLUENCE AND INTERACTION OFSAID FIRST AND SAID THIRD STREAMS OF FLUID.